package org.liufeng.course.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.liufeng.course.util.SignUtil;

/**
 * 请求处理的核心类
 *
 * @author liufeng
 * @date 2013-09-01
 */
public class CoreServlet extends HttpServlet {
    private static final long serialVersionUID = 4440739483644821986L;

    /**
     * 请求校验（确认请求来自微信服务器）
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 微信加密签名
        String signature = request.getParameter("signature");
        // 时间戳
        String timestamp = request.getParameter("timestamp");
        // 随机数
        String nonce = request.getParameter("nonce");
        // 随机字符串
        String echostr = request.getParameter("echostr");

        PrintWriter out = response.getWriter();
        // 请求校验，若校验成功则原样返回echostr，表示接入成功，否则接入失败
        if (SignUtil.checkSignature(signature, timestamp, nonce)) {
            out.print(echostr);
        }
        out.close();
        out = null;
    }

    /**
     * 处理微信服务器发来的消息
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO 消息的接收、处理、响应
    }
}
